Boeing 787 Dreamliner - Mark Wagner [36]
Chapter 4
GOLF, MISSILES, AND DREAMLINERS
IT WAS A COLD, BRIGHT EARLY JANUARY DAY IN SEATTLE IN 2005 when the outside world got its first glimpse of a large piece of the Dreamliner’s radically new, composite fuselage structure. Gratefully exchanging the cold wind outside for the warm air inside Boeing’s Developmental Center by Boeing Field, the invited journalists stared for some seconds in silence at the blue-and-white-painted fuselage barrel sitting on its mobile tool fixture in a corner of the building.
This first view of any tangible part of the 7E7 was orchestrated by Boeing partly to prove that the new-technology twinjet and its large-scale composite materials were for real. The representative Section 47, an aft fuselage barrel, was the first all-composite one-piece development article and was to be followed by other large-scale test sections for different parts of the body.
“It’s the largest piece of pressure vessel carbon fiber ever made, and the first one like it in the world,” said Walt Gillette, standing in front of it like a proud new father. Stretching twenty-two feet long, and just over nineteen feet in diameter, it was selected for its challenging compound curvature as the best single unit to begin proving the process.
“This is a piece of aviation history,” said Walt Gillette about the first full-scale composite one-piece fuselage test section built to demonstrate the advanced production concepts that would define the 787. The twenty-two-foot-long, nineteen-foot-wide aft fuselage Section 47 incorporated advanced features such as co-cured stringers and was made from composite tape laid down by a computerized machine over a mold made from interlocking mandrels. The tape, presoaked in epoxy, was enclosed with caul plates and polymer bags and placed in the autoclave for curing. Under heat and pressure a chemical reaction transformed the composite into a toughened structure. This test specimen was later donated to Boeing’s Future of Flight Center in Everett. Mark Wagner
Based on the same fiber placement principle used by Raytheon in the manufacture of its composite-fuselage Premier I business jet, the test 7E7 fuselage sections would prove that the airliner could be successfully assembled from carbon fiber reinforced plastic (CFRP) tape laid down on a massive mold, or mandrel, by a computerized machine. The mandrel rotated as the tape was applied. Once completed, the entire structure was then wrapped, or bagged, and placed in the autoclave, a huge pressurized oven, for curing.
The piece looked huge and impressive, but despite its size Boeing deliberately played down the move to an all-composite fuselage and wing primary structure. The shift, it said, was an evolutionary, rather than a revolutionary, step. Chief Project Engineer Tom Cogan said, “It’s not really that much of a leap. We’ve been working with composite components for more than thirty years, and the reason we didn’t go for an all-composite aircraft in the past was cost.” He offered another intriguing perspective. “Think about it in reverse. If we built aircraft out of composites and wanted to go to aluminum, then we wouldn’t be able to do it. Why should you? It corrodes, it fatigues, and it needs more maintenance.”
Still, the skeptics were vocal and felt the decision to opt for an all-composite primary structure was a massive risk for a large airliner. Although predominantly composite aircraft such as the Premier 1 and Northrop Grumman B-2A had proved structurally sound, they argued that issues critical to commercial certification, such as crash-worthiness and lightning protection, were not yet properly thought through. Airbus warned the airlines considering the 7E7 about the vulnerability of the material to accidental, everyday damage caused by collisions with baggage and catering trucks.
Ironically Airbus, which had played the technology trump card as its best way into the commercial market for the past thirty years, had itself pioneered much